Performance study of different numerical methods for modeling the vertical water entry of a wedge

Slamming is a very important phenomenon that happens in marine structures that are working in difficult circumstances. The design life of Wave Energy Converters, floating offshore wind turbines and other marine constructions is dramatically shortened by slamming, because of its ability to damage offshore structures. Since many offshore structures have wedge-shaped bottoms, it is important to know the response of these structures to slamming loads for better designs. Maximum slamming loads are experienced by the offshore structures during vertical water entry. This paper studies the fluid–structure interaction of a 2D wedge during vertical water entry. Though various numerical methods and analytical formulations exist for modeling the water entry of wedge-shaped objects, there is no like-to-like comparison between the methods. This paper compares the splash zone and loads on the wedge due to FSI using three numerical methods viz., the Arbitrary Lagrangian Eulerian (ALE) method, the Finite Volume Method (FVM), and Smoothed Particle Hydrodynamics (SPH). Conventional methods like FVM and ALE need grid generation, while SPH is a relatively novel method that uses lagrangian particles to represent the domain. As SPH reduces the modeling time and handles continuously evolving boundaries, this paper also throws light on the performance of SPH in modeling dynamic phenomena like slamming. ALE and SPH methods are solved using explicit time stepping, while FVM employs implicit time stepping. All the numerical models captured the fluid velocity fields well, excluding SPH. Other parameters, like pressures, are comparable to the analytical values besides the fluid velocity field values.